The heating of precooked or partially precooked food items in a quick service commercial context is an important application of oven technology. In this regard, conventional microwave ovens are frequently located at convenience stores for use by the customer or clerk in heating food items purchased at the stores. However, the microwave heating process causes texture and taste problems in the finished products, particularly in pizza crusts and other breaded items. Until this invention, no way has been found to employ conventional, non-microwave, heating methods to prepare hot foods such as hamburgers and pizza within the convenience store constraints of low labor input, low capital cost, low maintenance, compact size and short preparation time.